A polymorphism rs6815464 in the macrophage erythroblast attacher gene is associated with low bone mineral density in postmenopausal Japanese women.

Background And Purposes: Osteoporosis and osteopenia are multifactorial diseases characterized by low bone mineral density (BMD) and are susceptible to genetic and environmental risk factors. The macrophage erythroblast attacher (MAEA) was discovered as a protein to mediate the attachment of erythroid cells to macrophages and is essential for bone marrow hematopoiesis. MAEA is expressed in a wide range of cells and tissues including osteoblasts and osteoclasts. Recent studies have shown that a single nucleotide polymorphism (SNP) rs6815464 (C/G) in the MAEA gene increases the susceptibility of type 2 diabetes mellitus. However, the contribution of MAEA to bone metabolism remains unknown. Therefore, we performed this study to evaluate the association between MAEA polymorphism and low BMD.

Methods: In a cross-sectional study with postmenopausal Japanese women living in the Yokogoshi area, Niigata City, we evaluated whether rs6815464 was associated with low BMD. Blood samples were collected from 353 subjects (age 63.8 ± 5.4 years). The MAEA genotype was determined by TaqMan assay. BMD was assessed by dual-energy X-ray absorptiometry at the lumbar spine (L2-L4), hip and femoral neck. Low BMD was defined as a T-score <-1.

Results: The percentage of subjects with low BMD in the lumbar spine, total hip and femoral neck were 71%, 75% and 84% respectively. After adjusting age, BMI, HbA1c, smoking and alcohol consumption, the G-allele carriage was found to be associated with low BMD of total hip (odds ratio = 2.11, 95% CI: 1.14-3.91, P = 0.018), but not of the lumbar spine or femoral neck.

Conclusion: The MAEA gene polymorphism rs6815464 was associated with low hip BMD in postmenopausal Japanese women.